稀土种类和加入量对az系镁合金组织的影响本科毕业设计.doc

( 二 〇 一 五 年 五 月 摘要 AZ系镁合金由于具有诸多良好的性能，成为了近年来的研究热点。镁合金作为目前最轻质的铸造合金，低密度、高比强度、良好的电磁屏蔽性，在航空航天电子、汽车等诸多领域得到了应用。目前普遍研究发现，在镁合金中加入稀土元素，能够改善合金组织，提升合金力学性能。但是对于具体加入多少，研究结果不尽相同，说法也不一致。为了更好地研究和发现稀土对镁合金的影响，我们设计制作了不同Ce含量的稀土-镁合金，通过其硬度、强度、伸率、XD、金相组织测分析不同稀土含量对其性能的影响。 课题以常见的AZ91D镁合金为研究主要对象，加入含量分别为0%、0.3%、0.6%、0.9%的稀土Ce，构成了加入单一稀土、不同稀土含量的AZ91D-Ce系列合金。通过压铸成型获得所需要的试件，使用蔡司光学显微镜、X射线衍射仪、显微硬度计、SHT-4605型微机控制电液伺服万能试验机等分析手段对合金的微观组织和力学性能进行了观察分析。结果显示(1) 由于稀土Ce的加入，使得合金晶粒细化，除了合金中原有的α-Mg和共晶体的基本组织组成以外，生产了新相Al4Ce(2) 随着稀土Ce加入量的增多，镁合金的硬度、抗拉强度、伸率增大，其力学性能得到改善。并且在Ce含量为0.9%时，其综合力学性能最好Abstract AZ based alloys because of the many good performance, has become a hot topic in recent years. Magnesium alloys as the most lightweight cast alloy, low density, high strength, good electromagnetic shielding, aerospace. Electronics, automotive and other fields has been applied. Now generally it found that adding rare earth elements in the magnesium alloy, it is possible to improve the alloy to enhance the mechanical properties of the alloy. But for how much concrete was added, the results are not the same, saying inconsistent. In order to better study and found that the impact of rare earth magnesium alloys, we designed a different contents of Ce rare earth - magnesium alloy, by measuring its hardness, tensile strength, tensile elongation, XED microstructure analysis to test and influence of different rare earth content on its properties. Subject to common AZ91D magnesium alloy as the research main object, join contents were 0%, 0.3%, 0.6%, 0.9% rare earth elements Ce, constitute the added single rare earth, rare earth content of different AZ91D-Ce alloys. Specimens obtained by die casting needs, using Zeiss optical microscopy, X-ray diffractometer, microhardness, SHT-4605 microcomputer controlled electro-hydraulic servo universal testing machine analytical tools, etc. on the microstructure and mechanical properties were observation and analysis. The results showed that: (1) With the increase of the